The first we hear of Iskandar is from Amos, in a conversation about the gods that happens right after the British Museum incident: "[O]ur most important law, issued by Chief Lector Iskandar in Roman times, forbids unleashing the gods or using their power" (6.148). It kind of sets you up to believe he's already lived and died, right?
Imagine the kids' surprise when they meet Iskandar—the same Iskandar—in the flesh. Well, the wrinkly old flesh: "His skin was like lunch-bag paper—brown, thin, and crinkled. White linen robes hung loosely off his small frame. A leopard skin was draped around his shoulders, and his hand shakily held a big wooden staff" (13.41). At thousands of years old, it's no wonder he doesn't look like a homecoming king.
Iskandar was the last magician to be trained before the House had to go underground when the Romans conquered Egypt. At that time, the spell that was used to extend Iskandar's life was lost, so he's the last magician to have a lifespan of two thousand years. Being so old and powerful has its advantages: Iskandar chooses to speak in his native language, Alexandrian Greek, and everyone else just has to deal with it. Or, wait, is that a disadvantage?
When you're that old, you tend to have a different perspective on things. Iskandar tells Sadie how things were back in the old days, when Egypt fell to the Romans and things got really bad: "At the time I blamed everyone—the gods who used men to act out their petty quarrels, the Ptolemaic rulers who had driven Egypt into the ground, my own brethren in the House for becoming weak and greedy and corrupt. I communed with Thoth, and we agreed: the gods must be put away, banished…The new rules kept the House of Life intact for another two thousand years. At the time, it was the right choice" (27.24).
So, basically, when you are old enough to see empires rise and fall, you'll have a unique perspective on things. Iskandar is definitely a wise old dude, but even he can make mistakes.
When the kids first meet Iskandar, they're struck by how millions of tiny hieroglyphic symbols swirl in the air around him. This is because "[h]is presence is so strong, he makes the language of the universe visible simply by being in the room" (16.74). Whoa, neat.
Being old and powerful doesn't mean that Iskandar's completely stuck in his ways. He admits to Sadie that her mother saw things in the future "that made even this old man question some long-held beliefs" (15.112). Since he was the one to forbid the gods, he couldn't exactly be like, "Hey guys, sorry, I changed my mind, the gods are cool now." So having a long-standing position of authority can sometimes be a drawback to actually getting stuff done.
When Sadie and Carter visit the Land of the Dead, they see Iskandar's ba (since he's dead by then), and Iskandar tells them how their mother changed his mind: "She insisted that only the gods and the House together could prevail. The old way—the path of the gods—would have to be reestablished. I was a foolish old man. I knew in my heart she was right, but I refused to believe… and your parents took it upon themselves to act. They sacrificed themselves trying to put things right, because I was too stubborn to change. For that, I am truly sorry" (28.26).
So, when was the last time you had an apology from a two-thousand-year-old world leader? Yeah, that's what we thought.